KF4HOJ
Joined: | Sat, Apr 4th 1998, 00:00 | Roles: | N/A | Moderates: | N/A |
Latest Topics
Topic | Created | Posts | Views | Last Activity |
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DIY Crystal Radio - Capacitive Tuning | Aug 28th 2017, 05:14 | 1 | 9,184 | on 28/8/17 |
Field Soldering Without A Soldering Iron - Video Link | Mar 2nd 2015, 03:24 | 1 | 7,519 | on 2/3/15 |
How to Build A Portable Solar Power Supply Video Series | Mar 2nd 2015, 03:18 | 2 | 12,191 | on 11/2/18 |
Ground Rod Driver Tool - DIY | Feb 27th 2015, 03:05 | 1 | 8,027 | on 27/2/15 |
Grab N' Go Solar "Generator" Box - DIY | Feb 27th 2015, 02:58 | 1 | 11,623 | on 27/2/15 |
Crystal Radio DIY Video | Feb 27th 2015, 00:52 | 1 | 7,914 | on 27/2/15 |
Forum Rules Question | Feb 17th 2015, 13:53 | 1 | 6,503 | on 17/2/15 |
Is There A Foreign Operations Forum? | Apr 12th 2014, 12:22 | 3 | 7,475 | on 27/2/15 |
Latest Posts
Topic | Author | Posted On |
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DIY Crystal Radio - Capacitive Tuning | KF4HOJ | on 28/8/17 |
I found a 1997 ARRL article on a capacitor tuned crystal radio. I've tried many of these and none worked. I started with this design and modified it for both looks and function (new earphones require a change, different coil design). It works very well. You can tune in even very faint stations with little to no cross-talk. This is a link to the video I made about its construction. It includes the circuit diagram. https://www.youtube.com/watch?v=AaNpFYe5dSo |
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HBR 14 coils conversion to toroidal coils | cathoderay | on 21/3/15 |
I built some coils for non-radio purposes. I used the formulas from a book called, "LC Circuits". It's not very big, but it's really clear and concise. I bought cores for the freqs I wanted, then ran the calculations per the book. Wound them and tested them with a scope and variable oscillator (and precision capacitor). | ||
Field Soldering Without A Soldering Iron - Video Link | KF4HOJ | on 2/3/15 |
Video about how to do field soldering without a soldering iron, using matches, lighter, ... I tried many ways (and failed) until I found this simple trick about using the wire as it's own soldering iron. https://www.youtube.com/watch?v=udZja8xRElc |
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How to Build A Portable Solar Power Supply Video Series | KF4HOJ | on 2/3/15 |
These are links to 4 videos (basic level) I made on how to build a portable solar power supply (aka "generator"). Thought some might find it useful. Part 1 - Intro & Background https://www.youtube.com/watch?v=eIZ0cx-QKrk Part 2 - Power Output / Battery Matching https://www.youtube.com/watch?v=I_OGdvyDNpI Part 3 - Solar Panel / Controller Matching https://www.youtube.com/watch?v=NWnEqyoEIf8 Part 4 - Building Tips & Tricks https://www.youtube.com/watch?v=AWvz2jGno7o |
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Ground Rod Driver Tool - DIY | KF4HOJ | on 27/2/15 |
This is a video of how to make an inexpensive ground rod driver tool. It allowed me to put in a 3 meter long rod in just over 2 minutes flush against a wall. No mushrooming, no smashed fingers, no collateral damage (do know if there's anything underground before you drive!!!) I stopped about halfway down and got out a small sledgehammer to compare the difference and quickly went back to the driver tool. It fits on the end of a hammer drill. I have just a smaller size hammer drill and it works fine. Hope it's useful. https://www.youtube.com/watch?v=cP6fglxx7Ps KF4HOJ / HS0ZEY |